Process of solubilizing a perylenetetracarboxylic di-imide dyestuff and dyestuffs produced thereby



Patented Sept. 30, 1930 UNITED .STATES ANTHONY JAMES HAILWOOD, or BLACKLEYI; manonnsuna;nnenmnnsslelvon o.

BRITISH nxnsrorrs CORPORATION LIMITED, or mnncrrnsrun 'nnenennz J v rnocnss or SOLUBILIZING A rERYLENETETRAcAi-"iBoXYLIo ni i vtinu' vnvnsrrnrrs raonpounrnnannx F,

No Drawing. Application filed July 25, 1927, Serial no'izoaait, anaQimere EIaimam K111163519, 1m.

The present invention relates to improving the vatting properties of the dyestuffs prepared by the processes of the British. patent specification No. 26,690 of 1913. These vat dyestuffs will be referred to in this specification as perylenetetracarboxylic di-imide dyestuffs and they have the probable characteristic formula:

The above mentioned dyestuffs have some-' what inferior vatting properties due tothe insolubility of the leuco compound in the vat. The vat obtained with these dyestuifs is sensitive to alkaline hydrosulphite and the leuco compound comes out at once in flocks. For instance, the claret colored dyestuif prepared from naphthalimide by fusing with caustic alkali at from 280 C. to 300 C. is a water-insoluble powder or paste. It gives a sparingly alkali soluble leuco derivative and the sparing solubility of the same limits its application in dyeing. Attempts have been made to improve the vatting properties of these dyestuffs but they have all met with failure.

I have now, found new processes for converting these dyestuffs into an improved form. The improved dyestuffs are soluble or colloidally soluble and are suitable for vatting. They disperse readily in water or weak alkali and give on vatting in the usual manner a highly dispersed vat of considerable stability, from which dyeings may be more readily and satisfactorily obtained than is possible by the-use of the original dyestuffs.

The new process consists in treating the dry powdered d yestufli with sulphonating agents other than ordinary concentrated sulphuric acid, for example with oleum, or particularly with chlorosulphonic acid, at moderate temperatures, and after some time pouring the mixture on to water or ice. The precipitate is then filtered 0E, washed with a little water and the small residual acidity of the paste neutralized by caustic soda. The

product is then" either dried or i stored: ashapastei F The "product either. dry or 'asua paste on mixingwithn large quantity ofi warm water disperses through it, and on vatting this dispersionin' the usual manner,avat:or superiorqualitiesj is' obtained, from :which clalret" shades on cotton are obtained of un impaired fastness; "Ihe' superiority "of" the vat obtained from the disperseddyestufi is exhibitedmainly in-its greater-"dispersionstability Y and: more level dy eingf and? pane trating properties. I n

r The following exampl'es illustrate-my new processx The T particulardetails r however may varied in a considerable degree and the examples'do not limitlthe niethod'ot'carrying. out: my invention. The parts are' by weight. F 5 parts of perylenetetracarboxylic di-imi'defsuch as may b'e obtained by fusing naphthalene :1 8 dicarboxylio acid; 2 iniide with: caustic potash (see Ex am le'l of the British patentsFspec ifieation: No. '26,69 0 /'13 are chargedwinto l 28 parts of 20 per cent oleum and the 'temperaturea' raised: to 50* t C. for l'hour. EThG PI OdLlOt is then'cooled-and poured on to a mixture of 100 parts office and 50 parts of water, and the "precipitate filtered off? This is washed with a little we; er? an n n ef li tlral ew h causticsjoda i I 10 parts "of" 'peiylenetetracarboxy li'c di imide, such as may be obtained-twinin mph-thawe 1': 8 dicarboxylic ac'id iniide with caustic potash (see Example 1 of-the British patent specification No. 26,690/13) are charged into 50 parts of chlorosulphonic acid below 20 C. The temperature is then raised during 1 hour to 50 C. and maintained at this temperature for 1 hour. Hydrochloric acid gas is evolved during this process. The product, is then cooled and poured into a mixture of 200 parts of ice and 100 parts of water. The precipitate is filtered off, washed with a little water and the remaining paste made slightly alkaline with caustic soda and then represents the desired product.

The following example illustrates a method of using the new product in dyeing.

2 parts of the dyestufi powder or an equivalent amount of paste, as prepared in Example 1 or 2, are stirred into 1250-1500 parts of water at 5060 0., and 15 parts of caustic soda solution 76 Twad, are added followed by 4; parts of sodium hydrosulphite. The reduction is almost immediate. parts of the cotton are worked in this vat for hour, then rinsed in cold water and allowed to oxidize in the air. The cotton is then soaped in a boiling soap bath,-

rinsed in warm water and dried.

What I claim and desire to secureby Let- V ters Patent is 1. The process of converting a perylenetetracarboxylic di-imide dyestufl into a soluble or colloidally soluble form suitable for vatting, which comprises a treatment of the said dyestufi with chlorosulphonic acid, followed by reprecipitation of the dyestufi" by dilution.

2. The process of converting a perylenetetracarboxylic di-imide dyestuif into a soluble or colloidally soluble form suitable for vatting, which comprises a treatment of the saiddyestufl' with a sulphonating agent of the class consisting of oleum and chlorosulphonic acid, followed by reprecipitation of the dyestufi by dilution.

3. The process of converting a perylenetetracarboxylic di-imide dyestulf into a soluble or colloidally soluble form suitable for vatting, which comprises a treatment of the said dyestufi" with oleum, followed by reprecipitation of the dyestuff by dilution.

4. The improved form of a perylenetetracarboxylic di-imide dyestuif existing in a soluble or colloidally soluble condition suitable for vatting and'obtainable by treat-- ing an ordinary perylenetetracarboxylic diimide dyestutf with a sulphonating agent of the class consisting of oleum and chlorosulphonic acid, followed by reprecipitation by dilution, said 'dyestufi' in its improved form having the chemical properties of the original dyestufi but characterized by the fact that it yields with alkaline hydrosnlphite a clear vat of considerable stability when protected from oxidation. In testimony whereof I'aflix my signature.

ANTHONY JAMES HAILWOOD. 

